Extended maintenance for Symfony 2.4

Symfony 2.4 end of maintenance was reached at the end of July. But as migrating
to Symfony 2.5 proved to be difficult because of some bugs, we decided to
extend the maintenance until September 2014. So, expect a new release of
Symfony 2.4 at the end of August and probably a last one at the end of
September. After that, Symfony 2.4 will still receive security issue fixes until January 2015.

Symfony 2.5.3 is going to be released later today and it should fix all
problems with the migration from 2.4. If not, please open a ticket and explain the problem so
that we can work on a fix as soon as possible.